Re-entrant spin glass behaviour and large magnetocaloric effect in Er2PtSi3

We present the magnetic properties and magnetocaloric effect of ternary intermetallic compound Er2PtSi3 with the orthorhombic Ba2LiSi3-type structure. Dc magnetization, ac susceptibilit, magnetic relaxation, electrical resistivity and specific heat measurements indicate that this system undergoes two magnetic phase transitions from a paramagnetic state sequentially to an antifwerromagnetic state at T-N=5.4 K and then to a random spin freezing state at T-f=2.4 K. In addition, the large magnetocaloric effect is also observed for the Er2PtSi3 alloy. Near its Neel temperature T-N, the maximum magnetic entropy change, relative cooling power and maximum adiabatic temperature change are estimated to be 16.1 Jkg(-1)K(-1), 290 Jkg(-1) and 7.7 K, respectively, for a field change of 5 T. These results suggest that Er2PtSi3 should be classified as a re-entrant spin-glass system and can be considered as a potential low-temperature magnetic refrigeration material.